use stm32f4xx_hal::{
    adc::Adc,
    gpio::{
        AF5, Alternate, Analog, Input,
        gpioa::*,
        gpiob::*,
        gpiod::*,
        Output, PushPull, Pin,
    },
    hal::{self, blocking::spi::Transfer, digital::v2::OutputPin},
    spi::{Spi, NoMiso, TransferModeNormal},
    pac::{GPIOB, SPI2}
};